The Purfling/Soundhole Router Guide is a special attachment for your Dremel tool. It helps you cut channels for purfling (decorative strips) on violin plates or rosettes around guitar soundholes (round or oval). Here’s a simple summary:

1. **What It Does**:
   - It guides your Dremel tool to cut precise channels along edges or around soundholes.
   - It works well for tight curves and keeps the cutting distance consistent.

2. **How to Use It**:
   - Remove the plastic collar from your Dremel, attach the tool to the guide, and set the cutting depth.
   - You can adjust how far the cut is from the edge.
   - It’s easy to hold and gives you a clear view of your work.

3. **Size**:
   - The base is 2-3/4" x 1" (70.17mm x 25.40mm).
   - The sliding platform is 4-1/4" x 1" (108.41mm x 25.40mm).
   - The total height is 2" (50.80mm), plus a thumbscrew.

This tool makes it easier to cut clean, accurate channels for decorative work on instruments.